"Insects are cold-blooded, which means that their body
temperatures are regulated by the temperature of their
environment," NPMA public affairs officer Missy Henriksen said in
a statement. "In cold weather, insects' internal temperatures
drop, causing them to slow down. But in warm weather, they become
more active. Larvae grow at a faster rate, reproduction cycles
speed up, and they move faster."

Hot has been the watchword this year, with the first half of 2012
measuring up as the
warmest on record for the United States. June 2011 to June
2012 was also the warmest 12-month period since record-keeping
began in 1895, according to the National Oceanic and Atmospheric
Administration (NOAA).

Drought across the country's midsection can also exacerbate pest
problems, Henriksen said. When insects and arachnids can't find
moisture outside, they often head indoors. Areas where rain is
more frequent are likely to see increased mosquito breeding, she
added.

About 64 percent of the continental United States was
experiencing drought as of July 19. The
unusually hot summer has also contributed to incidents of
heat stroke, low water supply in some areas and blows to
agriculture.